Vibratory cable plows have been used for several years to lay cable, flexible pipe and the like beneath an upper surface of ground. The cable or pipe may be either pulled through the cut of the plow blade or a cable chute may be provided on the trailing edge of the plow blade for guiding the cable or pipe into the ground from a supply source preferably mounted on the tractor or other type of prime mover. Various types of vibrator assemblies or shakers have been connected to the plow blade to generate combined vertical/orbital motion thereby effectively reducing the drawbar pull or force required to pull the blade through the ground.
In a conventional cable-laying plow, the plow blade is supported by a frame assembly connected to the prime mover. The frame assembly typically includes two pairs of rigid and parallel side links that combine with forward and rearward frame members to form a parallelogram-type linkage assembly. The plow blade and vibratory assembly or mechanism are commonly supported by the rearward frame member. The vibrator assembly imparts substantially vertical vibrations in the plow blade when the prime mover is stationery and generally orbital vibrations in the blade as the blade is pulled through the ground. A hydraulic lift cylinder is connected to one pair of the side links for setting the depth of the plow blade and for raising the plow blade to a retracted or elevated position.
The rigidity of the links comprising a conventional plow blade frame assembly readily transfer vibrations to the prime mover thus causing discomfort for the operator. Moreover, the rigidity of the links comprising the frame assembly prevents the attack angle of the blade from changing during operation of the cable-laying plow. As may be appreciated, as the plow blade moves through the ground it occasionally tends to encounter large rocks, tree roots, and the like. The plow blade is often damaged as a result of its encounter with such subterranean conditions which are unobservable to the operator. Alternatively, when a plow blade encounters a large rock or tree root, the rigidity and nonforgiving nature of the frame assembly transfers vibrations and weight to the prime mover which can cause significant damage to the cable plow assembly and to the prime mover thus resulting in downtime to effect repairs and/or replacement of damaged or broken parts.
Thus, there is a need and a desire for a vibratory cable plow assembly wherein the plow blade is mounted by structure capable of reducing damage to the prime mover resulting from the plow blade unexpectedly engaging with subterraneous conditions and wherein vibrations imparted to the plow blade are isolated from being transmitted to the prime mover.